Combustion aiding means



Patented June 1, 1937 COMBUSTION AIDING MEANS William R. Hulbert, Daniel R. Schock, and Frank E. Thompson, Chicago, Ill., assignors, by direct and mesne assignments, to Olga. Craven Hulbert, Chicago, Ill.

Application May 29, 1933, Serial No. 673,465

8 Claims.

This invention relates to means for aiding combustion in'furnaces and the like of the type in which a body member exposed to the heat of the furnace is adapted to discharge a commingled blast of steam, air and furnace gases into the furnace.

An object of the present invention is to provide an improved apparatus of the above type to accomplish the novel results herein set forth l0 and with this end in view the improved means includes a heat exchange body member directly exposed to the heat of the firebox and provided with an extended path therethrough for atmospheric air, whereby the air is preheated before its discharge from the body member and before contact with the steam, a passage intermediate its length for admitting gases from the firebox to the body for commingling with the preheated air before said discharge and means for commingling steam under pressure and at a high velocity with the preheated air and firebox gases subsequent to preheating of the air and prior to the discharge of the commingled preheated air, firebox gases and steam from the body member.

In our improved means we thus provide that the steam is progressively raised in temperature Within the device to maintain and enhance its potential energy. i In the accompanying drawing, Figure 1 is a horizontal sectional view through a corner portion of a furnace fire-box and through a highly advantageous form of the present combustion device.

Fig. 2 is a vertical sectional view on the broken line 22 of Fig. 1, the section being on the middle line of the device;

Fig. 3 is an enlarged cross-sectional view on the line 33 of Fig. 2; and

Fig. 4 is a vertical sectional view through the steam nozzle and associated parts.

The device illustrated comprisesfirst a hollow elongated bulbous body Ill cast from highly refractory metal. Cast iron would serve, although 5 there are other much more refractory metals and other materials available in the open market,

and a highly refractory material is preferred.

For application in the corner of the fire-box the body H1 is specially shaped. It changes its direc- 5 tion at l I so as to extend at its outer end at right angles to front wall I3 of the fire-box and in line with the inner iron tube I 2 imbedded rigidly in that wall. Also imbedded in wall I3 is the outer iron tube l4 having the flange I5 and the 55 diametric cross piece 16 which medially defines a pair of openings I1 into the hollow interior of tube l4. At l8 the space betweentubes i2 and I4 is open: r

A pipe l9, used to hold parts together, is held rigid with the outer end of the body [0 'bya' pair of nuts 20 and 2| threaded on the pipe and clamping between'them the flat end 22 of body Ill. This pipe l9 passes loosely through the outer support l6, and the nut 24 threaded at the outer end of pipe l9 draws upon the body lll and causes the upper and lower stops 26, 26, Fig.2 (one shown dotted in Fig. 1) against the fixedstop or tube l2, and thus the body Ill is held rigidly. The body may be adjusted, by loosening'nut 21, so as to direct its outflow-higher or lower with respect to the fuel bed. i l l The pipe 21 within pipe 19 leads "to thest'eam supply through pipe connections 21a. A cover 28 protects the air entrance andhas anintake opening at 29, Fig; 2. '1

The body I0 has a pair of openings 30 admitting outer air into the hollow interior at end portion 3|, which hollow interiordiv i'des into two branches 32, and these come together in the hollow discharge end or nozzle 33-.

Within the enlarged middle part of the body is a substantially vertical passageway 9 defined by end walls 34, 35 and side wa1ls36, 31, and these end and side walls merge into the outer shell of the body, all the walls of which are integral with each other. Vertical passageways opens into dischargepassageway 33a by a tube 38 integral with end wall 35. l A support 40 extends between side walls 36' and 3"- and is integral therewith, and'azpipe lt'extends through this support 40pandrhasat-its free end a stream jet nipple 42 having ajet orifice at 43 and outwardly-flaring walls 44. Pipe 4| connects with steam pipe 21 at 45.

The body It] becomes highly heated by the gases playing about it and by radiant'hea't of the fire and fire-box walls, and the heat of body ill heats the air passing through it. At .the reduced passageways 32 the furnace heat is applied on all sides of substantially narrow and elongated bodies of air, thus heating the airintensively just before it is commingled with steam and furnace gases. The steam jet nipple is in vertical intermediate passageway 9. The part Ma of pipe 4! is exposed to the furnace gases in thatrpassageway and the temperature of the steam is thereby raised.

One of the important achievements is that .the amount of steam used is greatly reduced. This is due to the unusually ,large proportion of air entrained for discharge into the firebox. It will be noted from the dotted lines in Fig. 2 how the diverging steam-and-furnace-gas impinges against the inner surface of discharge nozzle 33, with the result that the maximum amount of air is drawn in through the passageways 32. The rate of travel of the air is very high, and we introduce into the fire-box a very much larger amount of air, in a given time, than according to any such device heretofore, and this is done with a greatly reduced quantity of steam. This air is also more intensely heated than heretofore, and, through the commingling of the steam, pre-heated air and furnace gases, the oxygen present is rendered highly available for its desired action.

The operation is as follows: Steam issues at high velocity as a comparatively fine jet from steam nozzle 42, the jet being somewhat smaller than what has been usual in devices of this general class. For example, in a device of given general proportions, where a prior device will employ a nozzle throat of about a quarter of an inch in diameter we will use a nozzle having a jet orifice of Venturi formation with a throat of about an eighth on an inch in diametenwhile producing the superior results herein pointed out, such as enhancing the velocity of the steam, etc.

The jet orifice 43 is desirably of a diameter at its smallest point of about an eighth of an inch, some variation being permissible up to say of an inch in some instances, with a wellrounded approach to this smallest diameter, and from this smallest diameter flares outwardly therefrom at an appropriate angle of divergence, as shown, whereby the orifice is of Venturi configuration to best control both pressures and velocities for the purposes of this invention.

The steam pressure in pipe 4| may be varied at valve 50 according to the needs for different installations or from time to time. Furnace gases are entrained at steam jet nipple 42 in proportion to the pressure used, at this point the steam being regenerated by the furnace gases and potential energy being restored to the steam, and the commingled steam and such gases flow through the steam-and-furnace-gas tube 38. This action entrains pre-heated air from the passageways 32, and this air is there commingled with the steam-and-furnace gases, and the commingled hot air, steam and furnace gases issue through the final discharge passageway 33a of discharge nozzle 33.

Various changes and modifications may be made without departing from the invention, and we contemplate as being included in these improvements all such changes, variations and departures' from what is thus specifically illustrated and described as fall within the scope of the appended claims.

We claim:

1. A combustion-aiding device of the character described comprising a hollow body adapted to extend into a fire-box and being open at one end portion to receive air and open at the other end portion to discharge into the fire-box, said body being enlarged intermediate its ends and having walls at said enlarged portion dividing the hollow interior of the body into branches thereat, said walls also defining a transversely-arranged intermediate passageway for fire-box gases, said intermediate passageway opening into the discharge end portion of the device, with means providing a jet of steam directed iq @Iltrain firebox gases in said intermediate passageway and commingle them with such steam and air in the discharge end portion of the device.

2. A combustion-aiding device of the character described comprising a hollow body having an intake for air and a discharge portion providing a discharge passageway, said body having walls defining an intermediate transverse passageway for furnace gases, said intermediate passageway having an opening into said discharge passageway coaxial with the discharge passageway, and a pipe for steam having a steam jet nipple in said intermediate passageway and being directed toward said opening.

3. In combination with a fire-box wall, an inner anchoring member and an outer anchoring member held by the fire-box wall and defining the end portions of an air passageway formed through the wall, a combustion-aiding device seated against said inner member, pipe means secured to said device and extending to said outer member, with means holding said pipe means to the outer member, and a steam pipe extending through said pipe means and into said device.

4. In a combustion-aiding device of the character described, the combination including a hollow metallic body of highly refractory material for exposure at least in part directly to the radiant heat of a firebox, said body having an intake portion and a discharge portion angular thereto providing therethrough a materially extensive pathway for the passage of outer air through the body into the firebox, whereby said air is highly preheated before discharge thereof from the body, a passageway through the body intermediate its length for admitting gases from the firebox thereinto for commingling with the preheated air before said discharge, and means for commingling steam under pressure and at high velocity with said preheated air and firebox gases in said body in the vicinity of the discharge end of said pathway and subsequent to preheating of the air but prior to discharge of the commingled preheated air, firebox gases and steam from the body.

5. In a combustion-aiding device of the class described for use with a furnace firebox, the combination of a hollow body having walls of a sinuous character exposed within the firebox to firebox heat to become highly heated thereby, said body having a bulbous enlargement intermediate its length and a restricted discharge nozzle of somewhat Venturi formation, a steam jet nipple also of somewhat Venturi formation within the body coaxial with the discharge nozzle but terminating in said bulbous enlargement short of the discharge nozzle, means associated with the bulbous enlargement immediately adjacent the steam jet nipple for the passage into the bulbous enlargement of furnace gases, and means for passing air into the bulbous enlargement from the end of the body opposite the discharge nozzle whereby commingled steam, preheated air and furnace gases are discharged together from the said nozzle into the firebox.

6. As an article of manufacture, an elongated hollow body of highly refractory metal, said body having a somewhat Venturi-shape discharge portion at one end thereof, an inlet portion at the other end having its axis at an angle to the axis of the discharge portion, and an intermediate somewhat bulbous portion, web-like members extending across the inlet portion and the bulbous portion respectively for supporting a central steam pipe, and a passageway into the bulbous portion adjacent the said support which extends through said bulbous portion.

7. Combustion-aiding means of the class described comprising, in combination with a furnace or the like, a hollow heat exchange body exposed to the heat of the furnace fire-box, means for admitting outer air through said body into the fire-box including an extended pathway through said body for preheating the air passing therethrough, a passage in said body intermediate its length for admitting gases from the fire-box for commingling with the air in the body, and means for commingling steam within the body under pressure at a high velocity with the preheated air and fire-box gases subsequent to preheating of the air and prior to discharge of the commingled preheated air, fire-box gases and steam from the body.

8. Combustion-aiding means of the class described comprising, in combination, with a furnace or the like, a hollow body exposed to the heat of the furnace fire-box, means for admitting outer air through said body into the fire-box including an extended pathway through said body, said body having walls of a sinuous character whereby the direction of said air is changed in said body and said air is preheated before the discharge from said body, a passage in said body intermediate its length for admitting gases from the fire-box for commingling with the air in the body, and means for commingling steam within the body under pressure at a high velocity with the preheated air and fire-box gases subsequent to preheating of the air and prior to discharge of the commingled preheated air, fire-box gases and steam from the body.

WILLIAM R. HULBERT. DANIEL R. SCHOCK. FRANK E. THOMPSON. 

